From version 9.3.28 to version 9.4.11 the recommended method is to update, using this method does not lose the personal information you have in the internal memory.
Clean installation only in case you experience errors after having updated, in this case you must first backup all the personal...
I had my SD card formatted in the exFAT file system but Android 9 can not read it, I backed up the information on my SD card, I changed the format to the FAT32 file system, I copied the information back, and then Android 9 could read it.
I had my SD card formatted in the exFAT file system but Android 9 can not read it, I backed up the information on my SD card, I changed the format to the FAT32 file system, I copied the information back, and then Android 9 could read it.